Turbidity, CO2 and chlorine gas

Monitoring turbidity, carbon dioxide (CO2) and chlorine gas in pool water and water treatment facilities is essential to guarantee the safety and quality of the water for bathers.

What is pool water turbidity and why does it matter?

Turbidity is a measurement of the cloudiness or haziness of water caused by the presence of suspended particles such as algae, dirt, body oils or coagulated organic matter. High turbidity is not only an aesthetic problem — it also indicates that the disinfection and filtration systems may not be working correctly.

• Turbidity meters: these devices measure the level of suspended particles in NTU units (Nephelometric Turbidity Units) and are used both in swimming pools and in drinking water treatment plants.
• Recommended turbidity value: pool water should have a turbidity of less than 0.5 NTU to guarantee visibility and safe disinfection.

CO2 measurement in pools

Carbon dioxide (CO2) dissolved in pool water directly affects the pH level. High CO2 concentrations lower the pH, which can affect the efficacy of chlorine and cause irritation in bathers eyes and skin.

• CO2 sensors: monitor dissolved carbon dioxide levels in real time and are especially important in indoor pools, where ventilation may be limited.
• Keeping CO2 under control helps maintain a stable pH and reduces the need for corrective chemical treatments.

Chlorine gas detection

Chlorine gas (Cl2) can be generated in pool environments as a by-product of the reaction between chlorine and organic matter. At high concentrations it is toxic and hazardous to health, especially in indoor or enclosed pool areas.

• Chlorine gas detectors: fixed or portable sensors that continuously monitor the concentration of Cl2 in the air around the pool and trigger alarms if safe levels are exceeded.
• Installing a chlorine gas detector is strongly recommended in indoor public pools to comply with occupational health and safety regulations.

How to choose the right sensor

When selecting a turbidity, CO2 or chlorine gas sensor, consider the type of installation (indoor or outdoor), the required measurement range, and the compatibility with your existing monitoring and automation system. At Mercapool we can advise you on the best solution for your pool.